The 3D printer industry has experienced significant growth in recent years. Much of this growth is due to improvements in 3D printing technology that have made possible the construction of 3D printers that are sufficiently small and inexpensive to be offered to the general consumer.
To perform a print, a 3D printer machine typically obtains a design of a CAD model from a 3D printable file (STL file) and applies an additive process by laying down successive layers of liquid, powder, paper or sheet material to build the model from a series of cross sections. These layers, which correspond to the virtual cross sections from the CAD model, are joined or automatically fused to create the final shape.
While traditional techniques such as injection molding can be less expensive for manufacturing polymer products in high quantities, additive manufacturing techniques used in 3D printing can be faster, more flexible and less expensive when producing relatively small quantities of parts.
In one 3D printing method known as fused deposition modeling, the desired model, part, or object is produced by extruding small amounts of material which harden immediately to form layers. Typically, a thermoplastic filament or metal wire is unreeled from a coil to supply material to an extrusion nozzle head. The nozzle head heats the material and turns the flow on and off. The extrusion nozzle head is mounted above a bed on which layers of the material are deposited and a desired object is built. Typically stepper motors or servo motors are employed to move the extrusion head and adjust the flow; the head can typically be moved in both horizontal and vertical directions. Control of this mechanism is typically done by a computer-aided manufacturing (CAM) software package running on a microcontroller.
Various polymers may be used, including acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polylactic acid (PLA), high density polyethylene (HDPE), etc.
Generally, a single extrusion nozzle head holds a single filament and therefore delivers a single color of the material. Many 3D printers include a single extrusion head and therefore offer a single color. Some existing 3D printers include two or three extrusion nozzle heads and therefore can offer two or three colors. Typically, the extrusion nozzle heads are mounted on a linear structure that moves back and forth above the bed on which the desired object is built.